Experimental Studies on the Nerve–Sensory Cell Relationship during Degeneration and Regeneration in Ampullar Nerves of the Frog Labyrinth

Gleisner, L.; Wersäll, Jan

doi:10.3109/00016487509124265

Cited by 21 publications

(5 citation statements)

References 51 publications

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“…Similar synaptic specializations have been reported for certain electroreceptor organs (Szabo and Wersall, 1970); however, they have never been reported at any central nervous system synapse, except within the pineal gland (Vollrath and Howe, 1976). Experiments on the regenerating lateral line suggest that the expression of normal synaptic bodies, with associated vesicles, does not require the presence of an afferent innervation (Jorgensen and Flock, 19761, and experiments on the frog crista ampullaris show that the synaptic body and associated vesicles remain following deafferentation (Gleissner and Wersall, 1974). Plasticity of these synaptic structures is suggested by studies on retina and pineal showing that the numbers of synaptic ribbons can change depending on the level of sensory stimulation (Wagner, 1973;Vollrath and Howe, 1976).…”

Section: Contributions Of Morphological Differences To Functional Promentioning

confidence: 63%

Ultrastructural differences among afferent synapses on cochlear hair cells: Correlations with spontaneous discharge rate

1996

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The major class of cochlear afferent fibers, the type-I or radial-fiber (RF) population, has been subdivided into three functional groups according to spontaneous discharge rate (SR): those with low SR have the highest acoustic thresholds, high SR fibers have the lowest thresholds and medium SR fibers are of intermediate sensitivity (Liberman [1978] J. Acoust. Soc. Amer. 63:442-455). Existing evidence from intracellular labeling studies at the light microscopic level (Liberman [1982a] Science 216:1239-1241) suggests that a single cochlear inner hair cell makes synaptic contact with representatives of all three functional groups; however, low and medium SR fibers are spatially segregated from high SR fibers around the hair cell circumference, and low and medium SR fibers are smaller in caliber than those with high SR. The present study extends to the ultrastructural level the structure-function correlations available via intracellular labeling. Analysis is based on serial section reconstruction of the synaptic contacts between 11 radial fibers of known SR and their target hair cells. Results suggest systematic differences in synaptic ultrastructure among fibers of the three SR groups: with decreasing SR, the size and complexity of the synaptic body (a presynaptic specialization characteristic of the peripheral afferent synapses in all hair cell systems and some other peripheral receptors) tend to increase, as does the associated number of synaptic vesicles. The possible functional significance of these trends is discussed in the context of other known structural and functional differences among the three SR groups.

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Section: Contributions Of Morphological Differences To Functional Promentioning

confidence: 63%

Ultrastructural differences among afferent synapses on cochlear hair cells: Correlations with spontaneous discharge rate

1996

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“…Fine filaments, a few vesicles, and flocculent material are present in those nerve terminals. Degenerative nerve terminals containing markedly swollen mitochondria and vacuoles as seen in surgically denervated neuroepithelium (17,36) have not been found. It is speculated that the nerve terminals have retracted rather than having left the debris.…”

Section: Nerve Terminalsmentioning

confidence: 96%

“…However, their observations are opposed by the work of Silverstein and Makimoto (35) who saw by light microscopy no signs of vestibular cell degeneration in cats when the vessels were intact at nerve sectioning. Sensory cells in the frog crista ampullaris survived total denervation for 1-2 wk without typical signs of ultrastrucrural damage (17). Gribenski (18) showed advanced degeneration of ampullar cristae in frog 4 wk after nerve division.…”

Section: Hair Cell-nerve Relationshipmentioning

confidence: 99%

“…The cristae of the sensory epithelia degenerated when more than 75% of the ampullar nerve was severed in squirrel monkeys (26), and degeneration of the cristae was indicated 1 mo after destruction of the frog Scarpa ganglion (18). Nevertheless, a recent study in the frog showed that sensory cells in the labyrinth survived total denervation for 1-2 wk without typical signs of ultrastructural damage (17). The work of Orr (31) represents the only previous study of the effect of acoustico-vestibular innervation on hair cells.…”

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confidence: 99%

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Disappearance of afferent and efferent nerve terminals in the inner ear of the chick embryo after chronic treatment with beta-bungarotoxin.

Hirokawa¹

1977

The Journal of Cell Biology

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fl-Bungarotoxin(fl-BT) was applied to chick embryos at 3-day intervals beginning on the 4th day of incubation to see the effect of chronically and massively applied fl-BT, and to investigate the hair cell-nerve relationship in the developing inner ear by electron microscopy. On the 10th day of incubation, nerve terminals had achieved contact with differentiating hair cells, but the acoustico-vestibular ganglion cells of treated animals were decreased in number to one-third of those of the control. By the 14th day, most of the ganglion cells degenerated and disappeared, and only a few nerve terminals were seen in the neuroepithelium. At this time, most of the hair cells lacked synaptic contacts with nerve terminals, but their presynaptic specialization remained intact and they showed evidence of continuing differentiation. On the 17th day, the acoustico-vestibular ganglion cells were completely absent. All the hair cells were devoid of afferent and efferent innervation but were fully differentiated on the 21st day. /3-BT was found to have a similar destructive effect on cultured spinal ganglion cells. The present study shows that fl-BT kills acoustico-vestibular and spinal nerve cells when applied chronically and massively during development. Furthermore, the differentiation of hair cells proceeds normally, and their presynaptic specializations are maintained when nerve terminals are absent during later developmental stages.

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“…In the vestibular system, the necessity of nerve fibers for the maintenance of sensory hair cells is controversial. It has been reported that vestibular sensory hair cells can be maintained after the degeneration of vestibular nerve fibers in cats and frogs (2,3), whereas the degeneration of vestibular sensory hair cells has been observed after denervation in monkeys and guinea pigs (4,5). To date, there has been no study regarding human vestibules.…”

mentioning

confidence: 95%

Are Vestibular Sensory Cells Preserved after Destruction of Scarpa??s Ganglion? A Study Based on Metastatic Tumors of Temporal Bone

Suzukawa

Yamasoba²,

Tsuzuku³

et al. 2005

Otology & Neurotology

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Experimental Studies on the Nerve–Sensory Cell Relationship during Degeneration and Regeneration in Ampullar Nerves of the Frog Labyrinth

Cited by 21 publications

References 51 publications

Ultrastructural differences among afferent synapses on cochlear hair cells: Correlations with spontaneous discharge rate

Ultrastructural differences among afferent synapses on cochlear hair cells: Correlations with spontaneous discharge rate

Disappearance of afferent and efferent nerve terminals in the inner ear of the chick embryo after chronic treatment with beta-bungarotoxin.

Are Vestibular Sensory Cells Preserved after Destruction of Scarpa??s Ganglion? A Study Based on Metastatic Tumors of Temporal Bone

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